1 files changed, 50 insertions, 0 deletions
diff --git a/activestorage/app/models/active_storage/attachment.rb b/activestorage/app/models/active_storage/attachment.rb
new file mode 100644
index 0000000000..874ba80ca8
--- /dev/null
+++ b/activestorage/app/models/active_storage/attachment.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require "active_support/core_ext/module/delegation"
+
+# Attachments associate records with blobs. Usually that's a one record-many blobs relationship,
+# but it is possible to associate many different records with the same blob. A foreign-key constraint
+# on the attachments table prevents blobs from being purged if they’re still attached to any records.
+class ActiveStorage::Attachment < ActiveRecord::Base
+  self.table_name = "active_storage_attachments"
+
+  belongs_to :record, polymorphic: true, touch: true
+  belongs_to :blob, class_name: "ActiveStorage::Blob"
+
+  delegate_missing_to :blob
+
+  after_create_commit :analyze_blob_later, :identify_blob
+  after_destroy_commit :purge_dependent_blob_later
+
+  # Synchronously deletes the attachment and {purges the blob}[rdoc-ref:ActiveStorage::Blob#purge].
+  def purge
+    delete
+    blob&.purge
+  end
+
+  # Deletes the attachment and {enqueues a background job}[rdoc-ref:ActiveStorage::Blob#purge_later] to purge the blob.
+  def purge_later
+    delete
+    blob&.purge_later
+  end
+
+  private
+    def identify_blob
+      blob.identify
+    end
+
+    def analyze_blob_later
+      blob.analyze_later unless blob.analyzed?
+    end
+
+    def purge_dependent_blob_later
+      blob&.purge_later if dependent == :purge_later
+    end
+
+
+    def dependent
+      record.attachment_reflections[name]&.options[:dependent]
+    end
+end
+
+ActiveSupport.run_load_hooks :active_storage_attachment, ActiveStorage::Attachment